W.Ivanow writes in "Brief Survey of the Evolution of Ismailism" (Holland, 1952, pp. 15-16) that, "The next two puppet rulers, Musta'li and Amir, had some claims to the title of the Imam. But when Amir was assassinated in 524/1130, leaving no male issue, al-Hafiz ascended the throne with the title of the mustawda Imam, i.e., acting as a regent on behalf of the supposed infant heir. A story was put into circulation to the effect that the baby was sent to Yamen. The faithful Musta'lians take this legend quite seriously." De Lacy O'Leary on the other hand writes in "A Short History of the Fatimid Khalifate" (London, 1923, p. 222) that, "The Khalif al-Amir left no son, but at the time of his death, one of his wives was pregnant, and it was possible that she might give birth to an heir." Makrizi writes in "Itti'az" (3rd vol., p. 137) that, "It was stated that Hafiz was acting as guardian for al-Amir's son to be born by one of al-Amir's pregnant women." Thus, Hafiz, the uncle of al-Amir took the power as a ruler.
Henceforward, the Fatimid rule embarked on its rapid decline. The supposed infant son of al-Amir is named, Tayyib, about two and half years old, but De Lacy O'Leary holds however that when al-Amir's wife was delivered, her child was a daughter (op. cit., p. 223). Anyhow, the chief guardian of Tayyib was Ibn Madyan, who is said to have hidden the minor Tayyib in a mosque called Masjid ar-Rahma. Makrizi tells that the infant son of al-Amir was carried in a basket after wrapping it up and covering it over with vegetables. Here in the mosque, a wet nurse cared for him. And all of this was done without Hafiz knowing anything about it. Makrizi also writes that Tayyib was arrested and killed. The followers of Tayyib in Yamen however believed that he was hidden in 524/1130 and his line exists even today in concealment.